Expanded polystyrene, commonly used as cushioning material in helmets, has the characteristic of becoming plastically deformed after a single impact. As a result, in situations such as motorcycle accidents, its ability to absorb multiple impacts at the same location is diminished, potentially failing to provide sufficient protection for the head. In this study, we propose a structure that enables multiple impact absorption by applying the protective mechanism of the human brain—filling a space partitioned by expanded polystyrene with liquid. The performance of the proposed structure was evaluated using fluid-structure interaction analysis based on Arbitrary Lagrangian-Eulerian (ALE) method, and the results were compared against standard helmet specifications.
YANAMOTO et al. (Wed,) studied this question.